1. Field of the Invention
The invention relates to an implantable line having an elongated line body and a function conductor extending in the longitudinal direction of the line body, acting to implement a medical function of the line. Such lines are in particular stimulation electrode lines (hereinafter also referred to as “electrodes”) of heart pacemakers or shock electrode lines of implantable defibrillators but also catheters containing an elongated conductive structure.
2. Description of the Related Art
Medical implants such as the pacemakers and defibrillators mentioned above often form an electric connection inside the patient's body. Such a connection serves to measure electric signals and/or to stimulate body cells. This connection is often embodied as an elongated electrode. At the present time, electric signals are transmitted between the implant and the electrode contacts, which include but are not limited to tips, rings, HV shock coils and sensors with materials that are good conductors.
If a system comprising an implant and an electrode is exposed to strong interference fields such as EMI or MRI, unwanted malfunctions may occur, specifically resulting in heating of parts of the system or electric malfunctions (e.g., resets). The heating may cause damage to body tissues or even organs if the heated parts are in direct contact with the tissue. This is the case with the electrode tip in particular.
The cause of the unwanted malfunction is the interaction of the field with the elongated line structure of the electrode. The electrode acts as an antenna that receives energy from the surrounding fields. This energy on the lines being used therapeutically can be delivered by the antenna proximally to the implant or distally to the tissue via the electrode contacts.
The same problems also occur with other elongated conductive structures whose proximal end is not necessarily connected to an implant (e.g., in the case of catheters, temporary electrodes, etc.).